Solid–phase Extraction of Nickel Dimethylglyoximato Complex and Its Application to Determination of Nickel in Steel by Atomic Absorption Spectrometry

A solid-phase extraction method has been developed for the selective separation of nickel and applied to the determination of nickel in lead free-cutting steel. An appropriate amount of sample was dissolved in a mixture of hydrochloric acid, nitric acid, and hydrogen peroxide, and was finally prepared as a solution of 0.1 M tartaric acid–0.05% dimethylglyoxime (DMG)–0.05% Triton X-100 (pH 10). The sample solution was then passed through a column packed with polystyrene divinylbenzene copolymer resin to collect nickel as DMG complexes. Nickel complexes adsorbed on the column was eluted with 2 M hydrochloric acid and the effluent was evaporated to dryness. The residue was dissolved in 0.1 M hydrochloric acid and diluted to an appropriate volume with the same acid, followed by the determination of nickel by flame atomic absorption spectrometry. The present method was applied to the determination of nickel in a certified reference material JSS 519-1 (lead free-cutting steel, Japan Iron and Steel Federation) and 558±6 μg g−1 (n=3) was obtained (certified value: 560 μg g−1).